Solar cell array, solar cell module and manufacturing method thereof

ABSTRACT

A solar cell array comprises a plurality of cells. Each cell has a front surface on which light is incident when the cell is in operation and a back surface opposite to the front surface. The solar cell array also comprises a plurality of conductive wires. Adjacent cells are connected by the plurality of conductive wires. The solar cell array further comprises secondary grid lines disposed on the front surface of the respective cell. The secondary grid lines comprise middle secondary grid lines disposed in the middle of the respective cell and intersecting with the conductive wires, and edge secondary grid lines disposed on the edges of the respective cell and non-intersecting with the conductive wires. The solar cell array also comprises short grid lines disposed on the front surface of the cell. The short grid lines connect the edge secondary grid lines with the conductive wires or with at least one middle secondary grid line.

The present application claims priority to the following 41 Chineseapplications, the entireties of all of which are hereby incorporated byreference.

1. Chinese Patent Application No. 201410608576.6, filed Oct. 31, 2014;

2. Chinese Patent Application No. 201410606607.4, filed Oct. 31, 2014;

3. Chinese Patent Application No. 201410606601.7, filed Oct. 31, 2014;

4. Chinese Patent Application No. 201410606675.0, filed Oct. 31, 2014;

5. Chinese Patent Application No. 201410608579.X, filed Oct. 31, 2014;

6. Chinese Patent Application No. 201410608577.0, filed Oct. 31, 2014;

7. Chinese Patent Application No. 201410608580.2, filed Oct. 31, 2014;

8. Chinese Patent Application No. 201410606700.5, filed Oct. 31, 2014;

9. Chinese Patent Application No. 201410608469.3, filed Oct. 31, 2014;

10. Chinese Patent Application No. 201510085666.6, filed Feb. 17, 2015;

11. Chinese Patent Application No. 201510217625.8, filed Apr. 3, 2015;

12. Chinese Patent Application No. 201510217609.9, filed Apr. 3, 2015;

13. Chinese Patent Application No. 201520276309.3, filed Apr. 3, 2015;

14. Chinese Patent Application No. 201510217687.9, filed Apr. 3, 2015;

15. Chinese Patent Application No. 201510219182.6, filed Apr. 3, 2015;

16. Chinese Patent Application No. 201510217617.3, filed Apr. 3, 2015;

17. Chinese Patent Application No. 201520278183.3, filed Apr. 3, 2015;

18. Chinese Patent Application No. 201510217573.4, filed Apr. 3, 2015;

19. Chinese Patent Application No. 201510219540.3, filed Apr. 3, 2015;

20. Chinese Patent Application No. 201510218489.4, filed Apr. 3, 2015;

21. Chinese Patent Application No. 201510218563.2, filed Apr. 3, 2015;

22. Chinese Patent Application No. 201510219565.3, filed Apr. 3, 2015;

23. Chinese Patent Application No. 201510219436.4, filed Apr. 3, 2015;

24. Chinese Patent Application No. 201510218635.3, filed Apr. 3, 2015;

25. Chinese Patent Application No. 201520277480.6, filed Apr. 3, 2015;

26. Chinese Patent Application No. 201510219366.2, filed Apr. 3, 2015;

27. Chinese Patent Application No. 201520278409.X, filed Apr. 3, 2015;

28. Chinese Patent Application No. 201510218697.4, filed Apr. 3, 2015;

29. Chinese Patent Application No. 201510219417.1, filed Apr. 3, 2015;

30. Chinese Patent Application No. 201510221302.6, filed Apr. 3, 2015;

31. Chinese Patent Application No. 201510219353.5, filed Apr. 3, 2015;

32. Chinese Patent Application No. 201520280778.2, filed Apr. 3, 2015;

33. Chinese Patent Application No. 201510219378.5, filed Apr. 3, 2015;

34. Chinese Patent Application No. 201520280868.1, filed Apr. 3, 2015;

35. Chinese Patent Application No. 201510218574.0, filed Apr. 3, 2015;

36. Chinese Patent Application No. 201510217616.9, filed Apr. 3, 2015;

37. Chinese Patent Application No. 201520278149.6, filed Apr. 3, 2015;

38. Chinese Patent Application No. 201510218562.8, filed Apr. 3, 2015;

39. Chinese Patent Application No. 201510218535.0, filed Apr. 3, 2015;

40. Chinese Patent Application No. 201510217551.8, filed Apr. 3, 2015;and

41. Chinese Patent Application No. 201520276534.7, filed Apr. 3, 2015.

The present application is relevant to the following 10 U.S.applications, filed concurrently with the present application, theentireties of which are hereby incorporated by reference.

U.S. patent application Ser. No. ______ (Attorney Docket No. 14880-23),entitled “Solar Cell Module And Manufacturing Method Thereof,” filed______;

U.S. patent application Ser. No. ______ (Attorney Docket No. 14880-26),entitled “Solar Cell Array, Solar Cell Module And Manufacturing MethodThereof,” filed ______;

U.S. patent application Ser. No. ______ (Attorney Docket No. 14880-28),entitled “Solar Cell Module And Manufacturing Method Thereof,” filed______;

U.S. patent application Ser. No. ______ (Attorney Docket No. 14880-29),entitled “Solar Cell Array, Solar Cell Module And Manufacturing MethodThereof,” filed ______;

U.S. patent application Ser. No. ______ (Attorney Docket No. 14880-32),entitled “Solar Cell Unit, Solar Cell Array, Solar Cell Module AndManufacturing Method Thereof,” filed ______;

U.S. patent application Ser. No. ______ (Attorney Docket No. 14880-33),entitled “Solar Cell Unit, Solar Cell Array, Solar Cell Module AndManufacturing Method Thereof,” filed ______;

U.S. patent application Ser. No. ______ (Attorney Docket No. 14880-34),entitled “Solar Cell Unit, Solar Cell Array, Solar Cell Module AndManufacturing Method Thereof,” filed ______;

U.S. patent application Ser. No. ______ (Attorney Docket No. 14880-35),entitled “Solar Cell Unit, Solar Cell Array, Solar Cell Module AndManufacturing Method Thereof,” filed ______;

U.S. patent application Ser. No. ______ (Attorney Docket No. 14880-36),entitled “Solar Cell Unit, Solar Cell Array, Solar Cell Module AndManufacturing Method Thereof,” filed ______; and

U.S. patent application Ser. No. ______ (Attorney Docket No. 14880-44),entitled “Method For Manufacturing Solar Cell Module,” filed ______.

FIELD

The present disclosure relates to the field of solar cells, and moreparticularly, to solar cell arrays, solar cell modules and manufacturingmethods thereof.

BACKGROUND

A solar cell module is one of the most important components of a solarpower generation device. Sunlight irradiates to a cell from its frontsurface and is converted to electricity within the cell. Primary gridlines and secondary grid lines are disposed on the front surface andcover part of the front surface of the cell. As such, the part ofsunlight irradiating to the primary grid lines and the secondary gridlines are blocked by the grid lines and cannot be converted intoelectric energy within the cell. Thus, the primary grid lines and thesecondary grid lines need to be as fine as possible in order for thesolar cell module to receive more sunlight. However, the primary gridlines and the secondary grid lines serve to conduct current, and interms of resistivity, the finer the primary grid lines and the secondarygrid lines are, the smaller the cross section areas thereof are, whichcauses greater loss of electricity due to increased resistivity.Therefore, the primary grid lines and the secondary grid lines must bedesigned to achieve a balance between light blocking and electricalconduction, and to take the cost into consideration.

SUMMARY

In one aspect, a solar cell array comprises a plurality of cells. Eachcell has a front surface on which light is incident when the cell is inoperation and a back surface opposite to the front surface. The solarcell array also comprises a plurality of conductive wires. Adjacentcells are connected by the plurality of conductive wires. The solar cellarray further comprises secondary grid lines disposed on the frontsurface of the respective cell. The secondary grid lines comprise middlesecondary grid lines disposed in the middle of the respective cell andintersecting with the conductive wires, and edge secondary grid linesdisposed on the edges of the respective cell and non-intersecting withthe conductive wires. The solar cell array also comprises short gridlines disposed on the front surface of the cell. The short grid linesconnect the edge secondary grid lines with the conductive wires or withat least one middle secondary grid line.

In another aspect, a method for manufacturing a solar cell modulecomprises forming a cell array with a plurality of cells. The call arraycomprises a secondary grid line and a short grid line disposed on afront surface of the cell on which light is incident when the cell is inoperation. The secondary grid line includes a middle secondary grid linedisposed in the middle of the respective cell and intersected with aconductive wire. The secondary grid line also includes an edge secondarygrid line disposed on the edge of the respective cell andnon-intersected with the conductive wire. The short grid line connectsthe edge secondary grid line with the conductive wire or with at leastone middle secondary grid line. The method further comprises superposingan upper cover plate, a front adhesive layer, the cell array, a backadhesive layer and a back plate in sequence. The front surface of thecell faces the front adhesive layer, and a back surface thereof facingthe back adhesive layer. The method also comprises laminating thesuperposed layers to obtain the solar cell module.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a plan view of a solar cell array according to an embodimentof the present disclosure;

FIG. 2 is a longitudinal sectional view of a solar cell array accordingto an embodiment of the present disclosure;

FIG. 3 is a transverse sectional view of a solar cell array according toembodiments of the present disclosure;

FIG. 4 is a schematic diagram of a metal wire for forming a conductivewire according to embodiments of the present disclosure;

FIG. 5 is a plan view of a solar cell array according to anotherembodiment of the present disclosure;

FIG. 6 is a plan view of a solar cell array according to anotherembodiment of the present disclosure;

FIG. 7 is a schematic diagram of a metal wire extending reciprocallyaccording to embodiments of the present disclosure;

FIG. 8 is a schematic diagram of two cells of a solar cell arrayaccording to embodiments of the present disclosure;

FIG. 9 is a sectional view of a solar cell array formed by connecting,by a metal wire, the two cells according to FIG. 8;

FIG. 10 is a schematic diagram of a solar cell module according toembodiments of the present disclosure;

FIG. 11 is a sectional view of part of the solar cell module accordingto FIG. 10;

FIG. 12 is a schematic diagram of a solar cell array according toanother embodiment of the present disclosure.

REFERENCE NUMERALS

-   100 cell module-   10 upper cover plate-   20 front adhesive layer-   30 cell array-   31 cell-   31A first cell-   31B second cell-   311 cell substrate-   312 secondary grid line-   312A front secondary grid line-   312B back secondary grid line-   3121 edge secondary grid line-   3122 middle secondary grid line-   313 back electric field-   314 back electrode-   32 conductive wire-   32A front conductive wire-   32B back conductive wire-   321 metal wire body-   322 connection material layer-   33 short grid line-   40 back adhesive layer-   50 lower cover plate

DETAILED DESCRIPTION

Embodiments of the present disclosure will be described in detail andexamples of the embodiments will be illustrated in the drawings, wheresame or similar reference numerals are used to indicate same or similarmembers or members with same or similar functions. The embodimentsdescribed herein with reference to the drawings are explanatory, whichare used to illustrate the present disclosure, but shall not beconstrued to limit the present disclosure.

In prior art, primary grid lines and secondary grid lines of solar cellsare made of expensive silver paste, which requires a complicated andcostly manufacturing process of the primary grid lines and the secondarygrid lines. When the cells are connected into a module, the primary gridlines on the front surface of a cell are welded to the back electrodesof an adjacent cell by a solder strip. Consequently, the welding of theprimary grid lines is complicated, and the manufacturing cost of thecells is high.

In prior art, two primary grid lines are usually disposed on the frontsurface of a cell, and formed by applying silver paste to the frontsurface of the cell. The primary grid lines have a great width (forexample, up to over 2 mm), which consumes a large amount of silver, andmakes the cost high.

In prior art, a solar cell with three primary grid lines is provided,which still consumes a large amount of silver, and has a high cost.Moreover, three primary grid lines increase the shaded area, whichlowers the photoelectric conversion efficiency.

In addition, the number of the primary grid lines is limited by thesolder strip. The larger the number of the primary grid lines is, thefiner a single primary grid line is, and hence the solder strip needs tobe narrower. Therefore, it is more difficult to weld the primary gridlines with the narrower solder strip and to produce the narrower solderstrip, and thus the cost of the welding rises.

Consequently, from the perspective of lowering the cost and reducing theshaded area, the silver primary grid lines printed on the cell arereplaced with metal wires, for example, copper wires. The copper wiresare welded with the secondary grid lines to output the current. Sincethe silver primary grid lines are no longer used, the cost can bereduced considerably. The copper wire has a smaller diameter to reducethe shaded area, so the number of the copper wires can be raised up to10. This kind of cell may be called a cell without primary grid lines,in which the metal wire replaces the silver primary grid lines andsolder strips in the traditional solar cells.

The present disclosure provides a solar cell without primary grid lines,which needs neither primary grid line nor sold strip disposed on thecells, and thus lowers the cost. The solar cell without primary gridlines can be commercialized for mass production, is easy to manufacturewith simple equipment, especially at low cost, and moreover has highphotoelectric conversion efficiency.

However, in the field of solar cells, although the structure of thesolar cell is relatively uncomplicated, each component is relativelycrucial. The production of the primary grid lines takes various aspectsinto consideration, such as shaded area, electric conductivity,equipment, process, cost, etc., and hence becomes a difficult andcrucial issue in the solar cell technology. In the market, solar cellswith two primary grid lines were replaced with solar cells with threeprimary grid lines in 2007 through huge efforts of those skilled in theart. A few manufacturers launched solar cells with four primary gridlines around 2014. The concept of multiple primary grid lines is putforward in the recent years, but there is no relatively mature product.

Particularly, the metal wires are relatively fine and in a large number.Moreover, the metal wires are connected afterwards and have free ends.Due to the problem concerning the sophistication of the manufacturingequipment, it cannot be guaranteed that the fine and many metal wiresare connected with the cells in accurate positions, especially theaccuracy of the positions of the ends. In order to avoid short circuitscaused by the metal wire extending beyond the cells, the conductivewires are generally formed in the cells, in which case part of thesecondary grid lines at the edges of the cells cannot be connected withthe conductive wires well, thereby resulting in current loss.

The present disclosure seeks to solve at least one of the problemsexisting in the related art to at least some extent.

Thus, the present disclosure provides a solar cell array that is easy tomanufacture at low cost, and improves the photoelectric conversionefficiency.

The present disclosure further provides a solar cell module having theabove solar cell array. The solar cell module is easy to manufacture inlow cost, and improves the photoelectric conversion efficiency.

The present disclosure further provides a method for manufacturing thesolar cell module.

According to a first aspect of embodiments of the present disclosure, asolar cell array includes a plurality of cells and conductive wires,adjacent cells being connected by the conductive wires, secondary gridlines and short grid lines being disposed on a front surface of thecell. The secondary grid lines comprise middle secondary grid linesintersected with the conductive wires and edge secondary grid linesnon-intersected with the conductive wires, the short grid lines beingconnected with the edge secondary grid lines, and being connected withthe conductive wires or at least one middle secondary grid line.

In the solar cell array according to embodiments of the presentdisclosure, particularly regarding the solar cell without primary gridlines, the short grid lines are disposed on the front surface of thecell, so as to electrically connect the edge secondary grid linesnon-intersected with the conductive wires at the edge of the cell withthe conductive wires, thereby reducing current loss. The short gridlines can be formed by screen printing silver, which is easy to realizeand to control with high accuracy. The electric connection of all thefine grid lines and the conductive wires can be guaranteed, which lowersthe sophistication and difficulty of the process, and improves thephotoelectric conversion efficiency of the cell considerably.

The present disclosure further gives preference to connection ofadjacent cells by the plurality of conductive wires. The conductivewires are constituted by the metal wire. At least one metal wire extendsreciprocally between a surface of a first cell and a surface of a secondcell adjacent to the first cell, so as to form at least two conductivewires.

It is particularly concerned with the solar cell without primary gridlines, in which the conductive wires are formed by extendingreciprocally.

The conductive wires are constituted by the metal wire which extendsreciprocally. The metal wire extends reciprocally between the twoadjacent cells in a winding way to form a folded shape. The conductivewires of this structure are easy to manufacture in low cost, and canimprove the photoelectric conversion efficiency of the solar cell array.Moreover, the conductive wires are arranged in a winding way to avoidproblems due to cutting of the conductive wires. However, as for thiskind of cells, the edges of the cells cannot be reached in the manner ofwire winding. In view of the problem concerning the sophistication ofthe manufacturing process of the cell, the inventors of the presentdisclosure finds preferable embodiments after a long-term research, i.e.regarding the solar cell whose conductive wires are formed by wirewinding. The short grid lines are disposed on part of the secondary gridlines at the edges of the front surface of the cell, so as to avoidpartial current loss because the conductive wires arranged in thewinding way cannot reach the secondary grid lines at the edges of thecell, to further improve the photoelectric conversion efficiency of thesolar cell module.

According to a second aspect of embodiments of the present disclosure,the solar cell module includes an upper cover plate, a front adhesivelayer, a cell array, a back adhesive layer and a back plate superposedin sequence, the cell array being a solar cell array according to theabove embodiments.

According to a third aspect of embodiments of the present disclosure, amethod for manufacturing a solar cell module includes: forming a cellarray with a plurality of cells, in which secondary grid lines and shortgrid lines are disposed on a front surface of the cell; the secondarygrid lines include middle secondary grid lines intersected with theconductive wires and edge secondary grid lines non-intersected with theconductive wires, the short grid lines being connected with the edgesecondary grid lines, and being connected with the conductive wires orat least one middle secondary grid line; superposing an upper coverplate, a front adhesive layer, the cell array, a back adhesive layer anda back plate in sequence, in which a front surface of the cell faces thefront adhesive layer, a back surface thereof facing the back adhesivelayer, and laminating them to obtain the solar cell module.

The present disclosure relates to the solar cells connected by the metalwires. The short grid lines are disposed on the front surface of thecells to solve the accuracy problem of connection between the metal wireand the cell, to avoid current loss. The process is simple and easy torealize, and can lower the cost considerably.

Part of technical terms in the present disclosure will be elaboratedherein for clarity and convenience of description.

According to one embodiment of the present disclosure, referring toFIGS. 1-12, a cell 31 includes a cell substrate 311, secondary gridlines 312 disposed on a front surface (the surface on which light isincident) of the cell substrate 311, a back electric field 313 disposedon a back surface of the cell substrate 311, and back electrodes 314disposed on the back electric field 313. Thus, the secondary grid lines312 can be called the secondary grid lines 312 of the cell 31, the backelectric field 313 called the back electric field 313 of the cell 31,and the back electrodes 314 called the back electrodes 314 of the cell31.

The cell substrate 311 can be an intermediate product obtained bysubjecting, for example, a silicon chip to processes of felting,diffusing, edge etching and silicon nitride layer depositing. However,it shall be understood that the cell substrate 311 in the presentdisclosure is not limited to be formed by the silicon chip.

In other words, the cell 31 comprises a silicon chip, some processinglayers on a surface of the silicon chip, secondary grid lines on a frontsurface, and a back electric field 313 and back electrodes 314 on a backsurface, or includes other equivalent solar cells of other types withoutany front electrode.

A cell unit includes a cell 31 and conductive wires 32 constituted by ametal wire S.

A solar cell array 30 includes a plurality of cells 31 and conductivewires 32 which connect adjacent cells 31 and are constituted by themetal wire S. In other words, the solar cell array 30 is formed of aplurality of cells 31 connected by the conductive wires 32.

In the solar cell array 30, the metal wire S constitutes the conductivewires 32 of the cell unit, and extends between surfaces of the adjacentcells 31, which shall be understood in a broad sense that the metal wireS may extend between front surfaces of the adjacent cells 31, or mayextend between a front surface of a first cell 31 and a back surface ofa second cell 31 adjacent to the first cell 31. When the metal wire Sextends between the front surface of the first cell 31 and the backsurface of the second cell 31 adjacent to the first cell 31, theconductive wires 32 may include front conductive wires 32A extending onthe front surface of the cell 31 and electrically connected with thesecondary grid lines 312 of the cell 31, and back conductive wires 32Bextending on the back surface of the cell 31 and electrically connectedwith the back electrodes 314 of the cell 31. Part of the metal wire Sbetween the adjacent cells 31 can be called connection conductive wires.

In the present disclosure, descriptive terms, such as the cell substrate311, the cell 31, the cell unit, the cell array 30 and the solar cellmodule, are used only for the convenience of description, and shall notbe construed to limit the scope of the present disclosure.

All the ranges disclosed in the present disclosure include endpoints,and can be individual or combined. It shall be understood that theendpoints and any value of the ranges are not limited to an accuraterange or value, but also include values proximate the ranges or values.

In the present disclosure, orientation terms such as “upper” and “lower”usually refer to the orientation “upper” or “lower” as shown in thedrawings under discussion, unless specified otherwise; “front surface”refers to a surface of the solar cell module facing the light when themodule is in operation, i.e. a surface on which light is incident, while“back surface” refers to a surface of the solar cell module back to thelight when the module is in operation.

In the following, the solar cell array 30 will be described according tothe embodiments of the present disclosure with respect to the drawings.

As shown in FIG. 1 to FIG. 12, the solar cell array 30 according to theembodiments of the present disclosure comprises a plurality of cells 31and conductive wires 32; secondary grid lines 312 and short grid lines33 are disposed on a front surface of the cell; the secondary grid line312 comprises middle secondary grid lines 3122 intersected with theconductive wires 32 and edge secondary grid lines 3121 non-intersectedwith the conductive wires 32, the short grid lines 33 being connectedwith the edge secondary grid lines 3121, and being connected with theconductive wires 32 or at least one middle secondary grid line 3122.

The present disclosure relates to the solar cells connected by theconductive wires 32. The short grid lines 33 are disposed on the frontsurface of the cell 31 to solve the accuracy problem of connectionbetween the conductive wires 32 and the cell 31, to avoid current loss.The process is simple and easy to realize, and can lower the costconsiderably.

In the solar cell array 30 according to the embodiments of the presentdisclosure, adjacent cells 31 are connected by the plurality ofconductive wires 32. The conductive wires 32 are constituted by themetal wire S. At least one metal wire S extends reciprocally between asurface of a first cell 31 and a surface of a second cell 31 adjacent tothe first cell 31, so as to form at least two conductive wires 32.

The present disclosure is not limited to that all the conductive wiresare formed by winding the metal wire—the conductive wires can bepartially or completely formed by winding the metal wire. The reciprocalextension can be back and forth once. There is no limit to thetermination point of the reciprocal extension—the starting point and thetermination point can be at the same cell or at different cells, as longas the metal wire is winded.

In other words, the solar cell array 30 in the present disclosurecomprises at least two cells 31, each of which comprises a cellsubstrate 311, secondary grid lines 312 and short lines 33 disposed on afront surface of the cell substrate 311, and back electrodes 314disposed on a back surface of the cell substrate 311. Adjacent cells 31are connected by a plurality of conductive wires 32 constituted by ametal wire S which extends reciprocally between the adjacent cells 31.

The secondary grid lines 312 located at a side surface of the cellsubstrate 311 comprises two parts—one part of the secondary grid lines312 intersected with the conductive wires 32 and located in a middleposition of the cell substrate 311 to form middle secondary grid lines3122; the other part of the secondary grid lines 312 non-intersectedwith the conductive wires 32 and located at an edge of one side awayfrom the conductive wires 32 to form edge secondary grid lines 3121.

The edge secondary grid lines 3121 are provided with short grid lines 33connected with the conductive wires 32 or at least one middle secondarygrid line 3122. In specific embodiments, the short grid lines 33 arelocated at the edges of the cell 31 where the conductive wires 32 cannotreach when being winded, so as to avoid current loss.

Thus, in the solar cell array 30 according to the embodiments of thepresent disclosure, the conductive wires 32 are constituted by the metalwire which extends reciprocally. The conductive wires 32 of thisstructure extend reciprocally between two adjacent cells in a windingway to form a folded shape, which is easy to manufacture in low cost,and can improve the photoelectric conversion efficiency of the solarcell array 30. The conductive wires 32 are arranged in a winding way,such that problems caused by cutting of the conductive wires 32 can beavoided. Moreover, the short grid lines 33 are disposed on the secondarygrid lines 312 at the edge of the front surface of the cell 31, suchthat the current will not be wasted because the conductive wires 32cannot reach the secondary grid lines 312 at the edge of the cell 31, soas to further improve the photoelectric conversion efficiency of thesolar cell module.

The cell unit is formed by the cell 31 and the conductive wires 32constituted by the metal wire S which extends on the surface of the cell31. In other words, the solar cell array 30 according to the embodimentsof the present disclosure are formed with a plurality of cell units; theconductive wires 32 of the plurality of cells are formed by the metalwire S which extends reciprocally between the surfaces of the cells 31.

It shall be understood that the term “extending reciprocally” in thisdisclosure can be called “winding” which means that the metal wire Sextends between the surfaces of the cells 31. For example, referring toFIG. 1, in some circumstances, the metal wire extends between thesurfaces of the cells 31 in the same plane, such as either between thefront surfaces or between the bottom surfaces of the cells, to form aserpentine pattern. In some other circumstances, the metal wire Sextends between the surfaces of the cells 31 in multiple planes, such asbetween both the front surface of a cell and the bottom surface of anadjacent cell, to form a serpentine pattern. In yet other circumstances,the metal wire S extends between the surfaces of the cells 31 both inthe same plane and in multiple planes, such as sometimes between eitherthe front surfaces or the bottom surfaces of some adjacent cells, and atother times between both the front surface of a certain cell and thebottom surface of an adjacent cell, to form a serpentine pattern. Theplurality of conductive wires equals two or more passes of theserpentine shaped pattern. Preferably, two or more passes of theserpentine shaped pattern on the same plane are substantially parallelto each other. More preferably, all the passes of the serpentine shapedpattern on the same plane are substantially parallel to each other. Inthe present disclosure, it shall be understood in a broad sense that“the metal wire S extends reciprocally between surfaces of the cells31.” For example, the metal wire S may extend reciprocally between afront surface of a first cell 31 and a back surface of a second cell 31adjacent to the first cell 31; the metal wire S may extend from asurface of the first cell 31 through surfaces of a predetermined numberof middle cells 31 to a surface of the last cell 31, and then extendsback from the surface of the last cell 31 through the surfaces of apredetermined number of middle cells 31 to the surface of the first cell31, extending reciprocally like this.

In addition, when the cells 31 are connected in parallel by the metalwire S, the metal wire S can extend on front surfaces of the cells, suchthat the metal wire S constitutes a front conductive wire 32A.Alternatively, a first metal wire S extends reciprocally between thefront surfaces of the cells, and a second metal wire S extendsreciprocally between the back surfaces of the cells, such that the firstmetal wire S constitutes a front conductive wire 32A, and the secondmetal wire S constitutes a back conductive wire 32B.

When the cells 31 are connected in series by the metal wire S, the metalwire S can extend reciprocally between a front surface of a first cell31 and a back surface of a second cell 31 adjacent to the first cell 31,such that part of the metal wire S which extends on the front surface ofthe first cell 31 constitutes a front conductive wire 32A, and partthereof which extends on the back surface of the second cell 31constitutes a back conductive wire 32B. In the present disclosure,unless specified otherwise, the conductive wire 32 can be understood asthe front conductive wire 32A, the back conductive wire 32B, or thecombination thereof.

The term “extending reciprocally” can be understood as that the metalwire S extends reciprocally once to form two conductive wires 32 whichare formed by winding a metal wire S. For example, two adjacentconductive wires form a U-shape structure or a V-shape structure, yetthe present disclosure is not limited to the above.

In the solar cell array 30 according to the embodiments of the presentdisclosure, a plurality of conductive wires 32 of the cells areconstituted by the metal wire S which extends reciprocally; and theadjacent cells 31 are connected by the conductive wires 32. Hence, theconductive wires 32 of the cells are not necessarily made of expensivesilver paste, and can be manufactured in a simple manner without using asolder strip to connect the cells. It is easy and convenient to connectthe metal wire S with the secondary grid line and the back electrode, sothat the cost of the cells is reduced considerably.

Moreover, since the conductive wires 32 are constituted by the metalwire S which extends reciprocally, the width of the conductive wires 32(i.e. the width of projection of the metal wire on the cell) may bedecreased, thereby decreasing the shaded area of the conductive wires32. Further, the number of the conductive wires 32 can be adjustedeasily, and thus the resistance of the conductive wires 32 is reduced,compared with the conductive wires made of the silver paste, and theefficiency of photoelectric conversion is improved. Since the metal wireS extends reciprocally to form the conductive wires, when the cell array30 is used to manufacture the solar cell module 100, the metal wire Swill not tend to shift, i.e. the metal wire is not easy to “drift”,which will not affect but further improve the photoelectric conversionefficiency.

In the following, the solar cell array 30 according to specificembodiments of the present disclosure will be described with referenceto the drawings.

The solar cell array 30 according to a specific embodiment of thepresent disclosure is illustrated with reference to FIG. 1 to FIG. 3.

In the embodiment shown in FIG. 1 to FIG. 3, two cells in the solar cellarray 30 are shown. In other words, it shows two cells 31 connected witheach other via the conductive wires 32 constituted by the metal wire S.

It can be understood that the cell 31 comprises a cell substrate 311, asecondary grid line 312 (a front secondary grid line 312A) disposed on afront surface of the cell substrate 311, a back electric field 313disposed on a back surface of the cell substrate 311, and a backelectrode 314 disposed on the back electric field 313. In the presentdisclosure, it can be understood that the back electrode 314 may be aback electrode of a traditional cell, for example, printed by the silverpaste, or may be a back secondary grid line 312B similar to thesecondary grid line on the front surface of the cell substrate, or maybe multiple discrete welding portions, unless specified otherwise. Thesecondary grid line refers to the secondary grid line 312 on the frontsurface of the cell substrate 311, unless specified otherwise.

As shown in FIG. 1 to FIG. 3, the solar cell array in the embodimentincludes two cells 31A, 31B (called a first cell 31A and a second cell31B respectively for convenience of description). The metal wire Sextends reciprocally between the front surface of the first cell 31A (afront surface, i.e. an upper surface in FIG. 2) and the back surface ofthe second cell 31B, such that the metal wire S constitutes a frontconductive wire of the first cell 31A and a back conductive wire of thesecond cell 31B. The metal wire S is electrically connected with thesecondary grid line of the first cell 31A (for example, being welded orbounded by a conductive adhesive), and electrically connected with theback electrode of the second cell 31B.

In some embodiments, the metal wire extends reciprocally between thefirst cell 31A and the second cell 31B for 10 to 60 times. Preferably,as shown in FIG. 1, the metal wire extends reciprocally for 12 times toform 24 conductive wires, and there is only one metal wire. In otherwords, a single metal wire extends reciprocally for 12 times to form 24conductive wires, and the distance of the adjacent conductive wires canrange from 2.5 mm to 15 mm. Of course, the metal wire in the presentdisclosure is not limited to a single one—there may be multiple metalwires, or multiple metal wires are winded alone. In this embodiment, thenumber of the conductive wires is increased, compared with thetraditional cell, such that the distance between the secondary grid lineand the conductive wire which the current runs through is decreased, soas to reduce the resistance and improve the photoelectric conversionefficiency. In the embodiment shown in FIG. 1, the adjacent conductivewires form a U-shape structure, for convenience of winding the metalwire. Alternatively, the present disclosure is not limited to the above.For example, the adjacent conductive wires may form a V-shape structure.

More preferably, as shown in FIG. 4, the metal wire S includes a metalwire body 321 and a welding layer 322 coating the outer surface of themetal wire body. The metal wire is welded with the secondary grid linesand/or the back electrodes by the welding layer, such that it isconvenient to electrically connect the metal with the secondary gridlines and/or the back electrodes, and to avoid drifting of the metalwire in the connection process so as to guarantee the photoelectricconversion efficiency. Of course, the electrical connection of the metalwith the cell substrate can be conducted during or before the laminatingprocess of the solar cell module, and preference is given to the latter.

It shall be noted that in the present disclosure, the metal wire Srefers to a metal wire for extending reciprocally on the cells 31 toform the conductive wires 32; and the conductive wires 32 include ametal wire body 321 and a welding layer 322 coating the metal wire body321, i.e. the metal wire S comprises the metal wire body 321 and thewelding layer 322 coating the metal wire body 321. In the embodiments ofthe present disclosure, unless specified otherwise, the metal wirerepresents the metal wire S which extends reciprocally on the cells toform the conductive wires 32.

In some embodiments, preferably, the metal wire body 321 is a copperwire. Of course, the metal wire S can be a copper wire, too. In otherwords, the metal wire does not include the welding layer 322, but thepresent disclosure does not limited thereto. For example, the metal wirebody 321 can be an aluminum wire. Preferably, the metal wire S has acircular cross section, such that more sunlight can reach the cellsubstrate to further improve the photoelectric conversion efficiency.

In some embodiments, preferably, before the metal wire contact thecells, the metal wire extends under a strain, i.e. straightening themetal wire. After the metal wire is connected with the secondary gridlines and the back electrodes of the cell, the strain of the metal wirecan be released, so as to further avoid the drifting of the conductivewires when the solar cell module is manufactured, and to guarantee thephotoelectric conversion efficiency.

FIG. 5 is a schematic diagram of a solar cell array according to anotherembodiment of the present disclosure. As shown in FIG. 5, the metal wireextends reciprocally between the front surface of the first cell 31A andthe front surface of the second cell 31B, such that the metal wireconstitutes a front conductive wire of the first cell 31A and a frontconductive wire of the second cell 31B. In such a way, the first cell31A and the second cell are connected in parallel. Of course, it can beunderstood that preferably the back electrode of the first cell 31A andthe back electrode of the second cell 31B can be connected via a backconductive wire constituted by another metal wire which extendsreciprocally. Alternatively, the back electrode of the first cell 31Aand the back electrode of the second cell 31B can be connected in atraditional manner.

According to an embodiment of the present disclosure, the adjacent cells31 are connected by a plurality of conductive wires 32 constituted bythe metal wire which extends between a surface of a first cell 31 and asurface of a second cell 31 adjacent to the first cell 31.

Alternatively, the metal wire breaks off at a turn after being connectedwith the cells 31.

Preferably, the short grid lines 33 are connected with the edgesecondary grid line 3121 closest to the middle secondary grid lines 3122as shown in FIG. 1.

In some other specific embodiments of the present disclosure, the shortgrid lines 33 are connected with the conductive wires 32. Preferably,the short grid lines 33 and the metal wire at the front surface of thecell 31 are connected at a turn formed by reciprocal extension. An extrawelding point can be added to decrease the probability of breaking thewelding portion at the edges, and to further enhance the binding forceof the metal wire and the cell. The connection at the turn herein can beunderstood that the short grid lines 33 have intersection points withthe turns, i.e. the short grid lines 33 do not terminate at the turns.

According to an embodiment of the present disclosure, the short gridlines 33 are perpendicular to the secondary grid lines 312. The shortgrid lines 33 are, preferably, electrically connected with bended parts(ends proximate to the edges) of the conductive wires 32 on the frontsurface of the cell 31. More preferably, at least one short grid line 33is disposed corresponding with each bended part.

Since the distance between the bended parts of the conductive wires 32and the edges of the cell 31 is usually short, the short grid lines 33have a length of 1 to 10 mm, preferably 2.4 to 7 mm, a width of 0.05 to0.5 mm, and a thickness of 0.01 to 0.02 mm. There are 3 to 40,preferably 6 to 20 short grid lines.

The short grid lines 33 can be disposed in the same manner as thesecondary grid lines 312 on the front surface of the cell 31. Forexample, the short grid lines 33 can be printed along with the secondarygrid lines 312 by silk-screen printing at the same screen plate (whichcan be made of silver paste) as the front secondary grid lines 3121.

In some preferable embodiments of the present disclosure, the secondarygrid lines 312 have a width of 40 to 80 μm and a thickness of 5 to 20μm; there are 50 to 120 secondary grid lines, a distance betweenadjacent secondary grid lines ranging from 0.5 to 3 mm.

Alternatively, the metal wire breaks off at a turn after being connectedwith the cell 31. The metal wire breaks off at the turn after beingwelded with the cell 31 to form multiple independent conductive wires32.

The metal wire breaks off at the turn after being welded with the cell31 to separate the multiple conductive wires 32, which can decrease thestress between the cells and peeling strength at the joints of the metalwire and the cell, and further improve the photoelectric conversionefficiency of the solar cell array 30.

In some specific embodiments of the present disclosure, referring toFIG. 6, in a row of the cells 31, the adjacent cells are connected by ametal wire that extends reciprocally between a surface of a first cell31 and a surface of a second cell 31 adjacent to the first cell andconstitutes the conductive wire 32. Alternatively, a plurality of cells31 are arranged in an n×m matrix form, and in two adjacent rows of cells31, the metal wire extends reciprocally between a surface of a cell 31in a a^(th) row and a surface of a cell in a (a+1)^(th) row, in which nrepresents a column, m represents a row, and m−1≧a≧1.

Alternatively, in two adjacent rows of cells 31, the metal wire extendsreciprocally between a surface of a cell 31 at an end of the a^(th) rowand a surface of a cell 31 at an end of the (a+1)th row, the end of thea^(th) row and the end of the (a+1)^(th) row located at the same side ofthe matrix form.

Preferably, in the same row of cells 31, the metal wire extendsreciprocally between a front surface of a first cell 31 and a backsurface of a second cell 31 adjacent to the first cell 31. In twoadjacent rows of cells 31, the metal wire extends reciprocally between afront surface of a cell 31 at an end of the a^(th) row and a backsurface of a cell 31 at an end of the (a+1)^(th) row, to connect the twoadjacent rows of cells 31 in series.

In other words, the solar cell array 30 according to the embodiment ofthe present disclosure is arranged in an n×m matrix form by a pluralityof cells 31. Specifically, in the solar cell array 30, there aremultiple cells 31, and the cells are arranged in the n×m matrix form. Ina row of cells, the conductive wire 32 extends from a surface of a firstcell 31, and is electrically connected with a surface of a second cell31 adjacent to the first cell 31, to connect the cells 31 in the samerow; in two adjacent rows of cells, the conductive wire 32 extends froma surface of a cell 31 in a a^(th) row and is electrically connectedwith a surface of a cell in a (a+1)^(th) row, to connect the twoadjacent rows of cells 31, in which n represents a column, m representsa row, and m−1≧a≧1.

N can range from 2 to 30, m ranging from 2 to 18. Preferably, multiplecells 31 are arranged in a 12×6 or 10×6 matrix form, i.e. 10 or 12 cellsin a row, six rows in total. According to the preferable embodiment, thecells 31 in two adjacent rows are directly connected by the conductivewires without using the bus bars, which decreases the number of the busbars, shortens the connection distance, and reduces the resistance, soas to obtain higher electricity generation performance of the solar cellmodule.

Preferably, in the two adjacent rows of cells 31, the conductive wireextends from a surface of a cell 31 at an end of a a^(th) row and iselectrically connected with a surface of a cell at an end of a(a+1)^(th) row.

The solar cell array 30 according to another embodiment of the presentdisclosure is illustrated with reference to FIG. 6.

The solar cell array 30 according to the embodiment of the presentdisclosure comprises n×m cells 31. In other words, a plurality of cells31 are arranged in an n×m matrix form, n representing a column, and mrepresenting a row. More specifically, in the embodiment, 36 cells 31are arranges into six columns and six rows, i.e. n=m=6. It can beunderstood that the present disclosure is not limited thereto. Forexample, the column number and the row number can be different. Forconvenience of description, in FIG. 6, in a direction from left toright, the cells 31 in one row are called a first cell 31, a second cell31, a third cell 31, a fourth cell 31, a fifth cell 31, and a sixth cell31 sequentially; in a direction from up to down, the columns of thecells 31 are called a first column of cells 31, a second column of cells31, a third column of cells 31, a fourth column of cells 31, a fifthcolumn of cells 31, and a sixth column of cells 31 sequentially.

In a row of the cells 31, the metal wire extends reciprocally between asurface of a first cell 31 and a surface of a second cell 31 adjacent tothe first cell 31; in two adjacent rows of cells 31, the metal wireextends reciprocally between a surface of a cell 31 in a a^(th) row anda surface of a cell in a (a+1)th row, and m−1≧a≧1.

As shown in FIG. 6, in a specific example, in a row of the cells 31, themetal wire extends reciprocally between a front surface of a first cell31 and a back surface of a second cell 31 adjacent to the first cell 31,so as to connect the cells in one row in series. In two adjacent rows ofcells 31, the metal wire extends reciprocally between a front surface ofa cell 31 at an end of the a^(th) row and a back surface of a cell 31 atan end of the (a+1)^(th) row, to connect the two adjacent rows of cells31 in series.

More preferably, in the two adjacent rows of cells 31, the metal wireextends reciprocally between the surface of the cell 31 at an end of thea^(th) row and the surface of the cell 31 at an end of the (a+1)^(th)row, the end of the a^(th) row and the end of the (a+1)^(th) row locatedat the same side of the matrix form, as shown in FIG. 6, located at theright side thereof.

More specifically, in the embodiment as shown in FIG. 6, in the firstrow, a first metal wire extends reciprocally between a front surface ofa first cell 31 and a back surface of the second cell 31; a second metalwire extends reciprocally between a front surface of the second cell 31and a back surface of a third cell 31; a third metal wire extendsreciprocally between a front surface of the third cell 31 and a backsurface of a fourth cell 31; a fourth metal wire extends reciprocallybetween a front surface of the fourth cell 31 and a back surface of afifth cell 31; a fifth metal wire extends reciprocally between a frontsurface of the fifth cell 31 and a back surface of a sixth cell 31. Insuch a way, the adjacent cells 31 in the first row are connected inseries by corresponding metal wires.

A sixth metal wire extends reciprocally between a front surface of thesixth cell 31 in the first row and a back surface of a sixth cell 31 inthe second row, such that the first row and the second row are connectedin series. A seventh metal wire extends reciprocally between a frontsurface of the sixth cell 31 in the second row and a back surface of afifth cell 31 in the second row; a eighth metal wire extendsreciprocally between a front surface of the fifth cell 31 in the secondrow and a back surface of a fourth cell 31 in the second row, until aeleventh metal wire extends reciprocally between a front surface of asecond cell 31 in the second row and a back surface of a first cell 31in the second row, and then a twelfth metal wire extends reciprocallybetween a front surface of the first cell 31 in the second row and aback surface of a first cell 31 in the third row, such that the secondrow and the third row are connected in series. Sequentially, the thirdrow and the fourth row are connected in series, the fourth row and thefifth row connected in series, the fifth row and the sixth row connectedin series, such that the cell array 30 is manufacture. In thisembodiment, a bus bar is disposed at the left side of the first cell 31in the first row and the left side of the first cell 31 in the sixth rowrespectively; a first bus bar is connected with a conductive wireextending from the left side of the first cell 31 in the first row, anda second bus bar is connected with a conductive wire extending from theleft side of the first cell 31 in the sixth row.

As said above, the cells in the embodiments of the present disclosureare connected in series by the conductive wires—the first row, thesecond row, the third row, the fourth row, the fifth row and the sixthrow are connected in series by the conductive wires. As shown in thefigures, alternatively, the second and third row, and the fourth andfifth rows can be connected in parallel with a diode respectively toavoid light spot effect. The diode can be connected in a manner commonlyknown to those skilled in the art, for example, by a bus bar.

However, the present disclosure is not limited to the above. Forexample, the first and second rows can be connected in series, the thirdand fourth rows connected in series, the fifth and sixth rows connectedin series, and meanwhile the second and third rows are connected inparallel, the fourth and fifth connected in parallel. In such a case, abus bar can be disposed at the left or right side of corresponding rowsrespectively.

Alternatively, the cells 31 in the same row can be connected inparallel. For example, a metal wire extends reciprocally from a frontsurface of a first cell 31 in a first row through the front surfaces ofthe cells 31 in the second row to the sixth row.

In some specific embodiments of the present disclosure, a binding forcebetween the metal wire and the cells 31 ranges from 0.1 N to 0.8 N.That's to say, the binding force between the conductive wires 32 and thecells 31 ranges from 0.1 N to 0.8 N. Preferably, the binding forcebetween the metal wire and the cells ranges from 0.2 N to 0.6 N, so asto secure the welding between the cells and the metal wire, to avoidsealing-off of the cells in the operation and the transferring processand performance degradation due to poor connection, and to lower thecost.

The solar cell module 100 according to embodiments of the presentdisclosure is illustrated with reference to FIG. 10 and FIG. 11.

As shown in FIG. 10 and FIG. 11, the solar cell module 100 according toembodiments of the present disclosure includes an upper cover plate 10,a front adhesive layer 20, the cell array 30, a back adhesive layer 40and a back plate 50 superposed sequentially along a direction from up todown.

The front adhesive layer 20 and the back adhesive layer 40 are adhesivelayers commonly used in the art. Preferably, the front adhesive layer 20and the back adhesive layer 40 are polyethylene-octene elastomer (POE)and/or ethylene-vinyl acetate copolymer (EVA). In the presentdisclosure, polyethylene-octene elastomer (POE) and/or ethylene-vinylacetate copolymer (EVA) are conventional products in the art, or can beobtained in a method known to those skilled in the art.

In the embodiments of the present disclosure, the upper cover plate 10and the back plate 50 can be selected and determined by conventionaltechnical means in the art. Preferably, the upper cover plate 10 and theback plate 50 are transparent plates respectively, for example, glassplates.

In the process of manufacturing the solar cell module 100, theconductive wire can be first bounded or welded with the secondary gridlines and the back electrodes of the cell 31, and then superposed andlaminated.

Other components of the solar cell module 100 according to the presentdisclosure are known in the art, which will be not described in detailherein.

Specifically, the solar module 100 includes an upper cover plate 10, afront adhesive layer 20, the cell array 30, a back adhesive layer 40 anda back plate 50. The cell array 30 includes a plurality of cells 31, andadjacent cells 31 are connected by the plurality of conductive wires 32.The conductive wires 32 are constituted by the metal wire S. At leastone metal wire S extends reciprocally between a surface of a first cell31 and a surface of a second cell 31 adjacent to the first cell 31, soas to form at least two conductive wires 32. The front adhesive layer 20contacts with the conductive wires 32 directly and fills between theadjacent conductive wires 32.

That's to say, the solar cell module 100 according to the presentdisclosure includes an upper cover plate 10, a front adhesive layer 20,the cell array 30, a back adhesive layer 40 and a back plate 50superposed sequentially along a direction from up to down. The cellarray 30 includes a plurality of cells 31 and conductive wires 32 forconnecting the plurality of cells 31. The conductive wires areconstituted by the metal wire S which extends reciprocally betweensurfaces of two adjacent cells 31.

The conductive wires 32 are electrically connected with the cells 31, inwhich the front adhesive layer 20 on the cells 31 contacts with theconductive wires 32 directly and fills between the adjacent conductivewires 32, such that the front adhesive layer 20 can fix the conductivewires 32, and separate the conductive wires 32 from air and moisturefrom the outside world, so as to prevent the conductive wires 32 fromoxidation and to guarantee the photoelectric conversion efficiency.

Thus, in the solar cell module 100 according to embodiments of thepresent disclosure, the conductive wires 32 constituted by the metalwire S which extends reciprocally replace traditional primary grid linesand solder strips, so as to reduce the cost. The metal wire S extendsreciprocally to decrease the number of free ends of the metal wire S andto save the space for arranging the metal wire S, i.e. without beinglimited by the space. The number of the conductive wires 32 constitutedby the metal wire which extends reciprocally may be increasedconsiderably, which is easy to manufacture, and thus is suitable formass production. The front adhesive layer 20 contacts with theconductive wires 32 directly and fills between the adjacent conductivewires 32, which can effectively isolate the conductive wires from airand moisture to prevent the conductive wires 32 from oxidation toguarantee the photoelectric conversion efficiency.

In some specific embodiments of the present disclosure, the metal wire Sextends reciprocally between a front surface of a first cell and a backsurface of a second cell adjacent to the first cell; the front adhesivelayer 20 contacts with the conductive wires on the front surface of thefirst cell 31 directly and fills between the adjacent conductive wires32 on the front surface of the first cell 31; the back adhesive layer 40contacts with the conductive wires 32 on the back surface of the secondcell 31 directly and fills between the adjacent conductive wires 32 onthe back surface of the second cell 31.

In other words, in the present disclosure, the two adjacent cells 31 areconnected by the metal wire S. In the two adjacent cells 31, the frontsurface of the first cell 31 is connected with the metal wire S, and theback surface of the second cell 31 is connected with the metal wire S.

The front adhesive layer 20 on the first cell 31 whose front surface isconnected with the metal wire S is in direct contact with the metal wireS on the front surface of the first cell 31 and fills between theadjacent conductive wires 32. The back adhesive layer 40 on the secondcell 31 whose back surface is connected with the metal wire S is indirect contact with the metal wire S on the back surface of the secondcell 31 and fills between the adjacent conductive wires 32 (as shown inFIG. 2).

Consequently, in the solar cell module 100 according to the presentdisclosure, not only the front adhesive layer 20 can separate theconductive wires 32 on the front surfaces of part of the cells 31 fromthe outside world, but also the back adhesive layer 40 can separate theconductive wires 32 on the back surfaces of part of the cells 31 fromthe outside world, so as to further guarantee the photoelectricconversion efficiency of the solar cell module 100.

In some specific embodiments of the present disclosure, for a typicalcell with a dimension of 156 mm×156 mm, the solar cell module has aseries resistance of 380 to 440 mΩ per 60 cells. The present disclosureis not limited to 60 cells, and there may be 30 cells, 72 cells, etc.When there are 72 cells, the series resistance of the solar cell moduleis 456 to 528 mΩ, and the electrical performance of the cells is better.

In some specific embodiments of the present disclosure, for a typicalcell with a dimension of 156 mm×156 mm, the solar cell module has anopen-circuit voltage of 37.5-38.5 V per 60 cells. The present disclosureis not limited to 60 cells, and there may be 30 cells, 72 cells, etc.The short-circuit current is 8.9 to 9.4 A, and is not related to thenumber of the cells.

In some specific embodiments of the present disclosure, the solar cellmodule has a fill factor of 0.79 to 0.82, which is independent from thedimension and number of the cells, and can affect the electricalperformance of the cells.

In some specific embodiments of the present disclosure, for a typicalcell with a dimension of 156 mm×156 mm, the solar cell module has aworking voltage of 31.5-32 V per 60 cells. The present disclosure is notlimited to 60 cells, and there may be 30 cells, 72 cells, etc. Theworking current is 8.4 to 8.6 A, and is not related to the number of thecells.

In some specific embodiments of the present disclosure, for a typicalcell with a dimension of 156 mm×156 mm, the solar cell module has aconversion efficiency of 16.5-17.4%, and a power of 265-280 W per 60cells.

A method for manufacturing the solar cell module 100 according to theembodiments of the present disclosure will be illustrated with respectto FIG. 1 to FIG. 3 and FIG. 7 to FIG. 9.

Specifically, the method according to the embodiments of the presentdisclosure includes the following steps:

Forming a cell array 30 with a plurality of cells 31, in which secondarygrid lines 312 and short grid lines 33 are disposed on a front surfaceof the cell 31; the secondary grid lines 312 includes middle secondarygrid line 3122 intersected with conductive wires 32 and edge secondarygrid lines 3121 non-intersected with the conductive wires 32, the shortgrid lines 33 being connected with the edge secondary grid lines 3121,and being connected with the conductive wires 32 or at least one middlesecondary grid line 3122, in which specifically, the short grid lines 33can be manufactured in the same way as the secondary grid lines 312 onthe front surface of the cell 31, for example, screen printed inconjunction with the secondary grid lines and with the help of the samescreen printing plate as the front secondary gird lines 3121, and theshort grid lines 33 may be made of silver paste.

Superposing the upper cover plate 10, the front adhesive layer 20, thecell array 30, the back adhesive layer 40 and the back plate 50 insequence, in which the front surface of the cell 31 faces the frontadhesive layer 20, and the back surface thereof faces the back adhesivelayer 40, and laminating them to obtain the solar cell module 100.

In the specific embodiments of the present disclosure, the solar cellarray 30 comprises at least two cells 31, each of which comprises a cellsubstrate 311, secondary grid lines 312 and short grid lines 33 disposedon a front surface of the cell substrate 311, and back electrodes 314disposed on a back surface of the cell substrate 311. Adjacent cells 31are connected by a plurality of conductive wires 32 constituted by ametal wire S which extends reciprocally between the adjacent cells 31.

The secondary grid lines 312 located at a side surface of the cellsubstrate 311 comprises two parts—one part of the secondary grid lines312 intersected with the conductive wires 32 and located in a middleposition of the cell substrate 311 to form middle secondary grid lines3122; the other part of the secondary grid lines 312 non-intersectedwith the conductive wires 32 and located at an edge of one side awayfrom the conductive wires 32 to form edge secondary grid lines 3121.

The edge secondary grid lines 3121 are provided with short grid lines 33connected with the conductive wires 32 or at least one middle secondarygrid line 3122. The short grid lines 33 are located at the edges of thecell 31 where the conductive wires 32 cannot reach when being winded, soas to avoid current loss.

In the solar cell array 30 according to the embodiments of the presentdisclosure, the conductive wires 32 are constituted by the metal wirewhich extends reciprocally. The conductive wires 32 are constituted bythe metal wire which extends reciprocally. The conductive wires 32 ofthis structure extend reciprocally between two adjacent cells in awinding way to form a folded shape, which is easy to manufacture in lowcost, and can improve the photoelectric conversion efficiency of thesolar cell array 30. Moreover, the conductive wires 32 are arranged in awinding way, such that problems caused by breaking off the conductivewires 32 can be avoided. Moreover, the short grid lines 33 are disposedon the secondary grid lines 312 at the edge of the front surface of thecell 31, such that the current will not be wasted because the conductivewires 32 cannot reach the secondary grid lines 312 at the edge of thecell 31, so as to further improve the photoelectric conversionefficiency of the solar cell module.

The method includes the steps of preparing a solar array 30, superposingthe upper cover plate 10, the front adhesive layer 20, the cell array30, the back adhesive layer 40 and the back plate 50 in sequence, andlaminating them to obtain the solar cell module 100. It can beunderstood that the method further includes other steps, for example,sealing the gap between the upper cover plate 10 and the back plate 50by a sealant, and fixing the above components together by a U-shapeframe, which are known to those skilled in the art, and thus will be notdescribed in detail herein.

The method includes a step of forming a plurality of conductive wires bya metal wire which extends reciprocally surfaces of cells 31 and iselectrically connected with the surfaces of cells 31, such that theadjacent cells 31 are connected by the plurality of conductive wires toconstitute a cell array 30.

Specifically, as shown in FIG. 7, the metal wire extends reciprocallyfor 12 times under strain. As shown in FIG. 8, a first cell 31 and asecond cell 31 are prepared. As shown in FIG. 9, a front surface of thefirst cell 31 is connected with a metal wire, and a back surface of thesecond cell 31 is connected with the metal wire, such that the cellarray 30 is formed. FIG. 9 shows two cells 31. When the cell array 30has a plurality of cells 31, the metal wire which extends reciprocallyconnects the front surface of the first cell 31 and the back surface ofthe second cell 31 adjacent to the first cell 31, i.e. connecting asecondary grid line of the first cell 31 with a back electrode of thesecond cell 31 by the metal wire. The metal wire extends reciprocallyunder strain from two clips at two ends thereof. The metal wire can bewinded only with the help of two clips, which saves the clipsconsiderably and then reduces the assembling space.

In the embodiment shown in FIG. 9, the adjacent cells are connected inseries. As said above, the adjacent cells can be connected in parallelby the metal wire based on practical requirements.

The cell array 30 obtained is superposed with the upper cover plate 10,the front adhesive layer 20, the back adhesive layer 40 and the backplate 50 in sequence, in which a front surface of the cell 31 faces thefront adhesive layer 20, a back surface thereof facing the back adhesivelayer 40, and laminating them to obtain the solar cell module 100. Itcan be understood that the metal wire can be bounded or welded with thecell 31 when or before they are laminated.

The front adhesive layer 20 is disposed in direct contact with theconductive wires 32. In the process of laminating, the front adhesivelayer 20 melts and fills the gaps between adjacent conductive wires 32.The back adhesive layer 40 is disposed in direct contact with theconductive wires 32. In the process of laminating, the back adhesivelayer 40 melts and fills the gaps between adjacent conductive wires 32.

Example 1

Example 1 is used to illustrate the solar cell module 100 according tothe present disclosure and the manufacturing method thereof.

(1) Manufacturing a Metal Wire S

An alloy layer of Sn40%-Bi55%-Pb5% (melting point: 125° C.) is attachedto a surface of a copper wire, in which the copper wire has a crosssection of 0.04 mm², and the alloy layer has a thickness of 16 μm.Hence, the metal wire S is obtained.

(2) Manufacturing a Solar Cell Module 100

A POE adhesive layer in 1630×980×0.5 mm is provided (melting point: 65°C.), and a glass plate in 1633×985×3 mm and a polycrystalline siliconcell 31 in 156×156×0.21 mm are provided correspondingly. The cell 31 has91 secondary grid lines (silver, 60 μm in width, 9 μm in thickness) onits front surface, each of which substantially runs through the cell 31in a longitudinal direction, and the distance between the adjacentsecondary grid lines is 1.7 mm.

The short grid lines are printed at an edge of a side of the frontsurface of the cell by a secondary grid mesh at the same time ofprinting the secondary grid lines. The short grid lines areperpendicular to the secondary grid lines, and connected with theoutermost secondary grid line at the edge. The short grid line printedhas a length of 5.1 mm and a width of 0.2 mm. There are eight short gridlines.

The cell 31 has five back electrodes (tin, 1.5 mm in width, 10 μm inthickness) on its back surface. Each back electrode substantially runsthrough the cell 31 in a longitudinal direction, and the distancebetween the adjacent back electrodes is 31 mm.

60 cells 31 are arranged in a matrix form (six rows and ten columns). Intwo adjacent cells 31 in a row, a metal wire extends reciprocallybetween a front surface of a first cell 31 and a back surface of asecond cell 31 under strain. The metal wire extends reciprocally understrain from two clips at two ends thereof, and is intersected with theshort gird lines at the turns formed by reciprocal extension, so as toform 15 parallel conductive wires. The secondary grid lines of the firstcell 31 are welded with the conductive wires and the back electrodes ofthe second cell 31 are welded with the conductive wires. The distancebetween parallel adjacent conductive wires is 9.9 mm. 10 cells areconnected in series into a row, and six rows of the cells of such kindare connected in series into a cell array via the bus bar. Then, anupper glass plate, an upper POE adhesive layer, multiple cells arrangedin a matrix form and welded with the metal wire, a lower POE adhesivelayer and a lower glass plate are superposed sequentially from up todown, in which the front surface of the cell 31 faces the front adhesivelayer 20, such that the front adhesive layer 20 contacts with theconductive wires 32 directly; and the back surface of the cell 31 facesthe back adhesive layer 40, and finally they are laminated in alaminator, in which the front adhesive layer 20 fills between adjacentconductive wires 32. In such way, a solar cell module A1 is obtained.

Comparison Example 1

The difference of Comparison example 1 and Example 1 lies in that aconventional grid mesh is employed, and the short grid lines are notprinted at the same time of printing the secondary grid lines. In such away, a solar cell module D1 as shown in FIG. 12 is obtained.

Comparison Example 2

The differences between Comparison example 2 and Comparison example 1lie in that the cells are arranged in a matrix form; 15 metal wiresconnected in series are pasted at a transparent adhesive layer, and themetal wires are attached to the solar cells. In two adjacent cells, themetal wire connects a front surface of a first cell and a back surfaceof a second cell. Then, an upper glass plate, an upper POE adhesivelayer, and a first transparent adhesive layer, multiple cells arrangedin a matrix form and welded with the metal wire, a second transparentadhesive layer, a lower POE adhesive layer and a lower glass plate aresuperposed sequentially from up to down. Thus, a solar cell module D2 isobtained.

Example 2

Example 2 is used to illustrate the solar cell module 100 according tothe present disclosure and the manufacturing method thereof.

(1) Manufacturing a Metal Wire S

An alloy layer of Sn40%-Bi55%-Pb5% (melting point: 125° C.) is attachedto a surface of a copper wire, in which the copper wire has a crosssection of 0.03 mm², and the alloy layer has a thickness of 10 μm.Hence, the metal wire S is obtained.

(2) Manufacturing a Solar Cell Module

A EVA adhesive layer in 1630×980×0.5 mm is provided (melting point: 60°C.), and a glass plate in 1650×1000×3 mm and a polycrystalline siliconcell 31 in 156×156×0.21 mm are provided correspondingly. The cell 31 has91 secondary grid lines (silver, 60 μm in width, 9 in thickness) at itsfront surface, each of which substantially runs through the cell 31 in alongitudinal direction, and the distance between the two adjacentsecondary grid lines is 1.7 mm. The cell 31 has five back electrodes(tin, 1.5 mm in width, 10 μm in thickness) on its back surface. Eachback electrode substantially runs through the cell 31 in thelongitudinal direction, and the distance between the two adjacent backelectrodes is 31 mm.

The short grid lines are printed at an edge of a side of the frontsurface of the cell by a newly designed secondary grid mesh at the sametime of printing the secondary grid lines. The short grid lines areperpendicular to the secondary grid lines, and connected with theoutermost secondary grid line at the edge. The short grid line printedhas a length of 3.4 mm and a width of 0.1 mm. There are ten short gridlines.

60 cells 31 are arranged in a matrix form (six rows and six columns). Intwo adjacent cells 31 in a row, a metal wire extends reciprocallybetween a front surface of a first cell 31 and a back surface of asecond cell 31 under strain. The metal wire extends reciprocally understrain from two clips at two ends thereof, and is intersected with theshort gird lines at the turns formed by reciprocal extension, so as toform 20 parallel conductive wires. The secondary grid lines of the firstcell 31 are welded with the conductive wires and the back electrodes ofthe second cell 31 are welded with the conductive wires. The distancebetween parallel adjacent conductive wires is 7 mm. 10 cells areconnected in series into a row, and six rows of the cells of such kindare connected in series into a cell array via the bus bar. Then, anupper glass plate, an upper POE adhesive layer, multiple cells arrangedin a matrix form and welded with the metal wire, a lower POE adhesivelayer and a lower glass plate are superposed sequentially from up todown, in which the front surface of the cell 31 faces the front adhesivelayer 20, such that the front adhesive layer 20 contacts with theconductive wires 32 directly; and the back surface of the cell 31 facesthe back adhesive layer 40, and finally they are laminated in alaminator, in which the front adhesive layer 20 fills between adjacentconductive wires 32. In such way, a solar cell module A2 is obtained.

Example 3

The solar cell module is manufactured according to the method in Example2, but the difference compared with Example 2 lies in that the shortgrid lines are printed at an edge of a side of the front surface of thecell by a secondary grid mesh at the same time of printing the secondarygrid lines. The short grid lines are perpendicular to the secondary gridlines, and connected with the outermost secondary grid line at the edge.The short grid line printed has a length of 5.1 mm and a width of 0.15mm. There are ten short grid lines. The turn formed by reciprocalextension is located between the second and the third short grid lines.The short grid lines are intersected with the third secondary grid line.In such a way, a solar cell module A3 is obtained.

Example 4

The solar cell module is manufactured according to the method in Example2, but the difference compared with Example 2 lies in that after beingwelded the secondary grid lines, the metal wire cuts the arc segments atthe turns to form separate and parallel 20 metal wires. The distancebetween adjacent parallel primary grid lines is 7 mm. In such a way, asolar cell module A4 is obtained.

Example 5

The solar cell module is manufactured according to the method in Example3, but the difference compared with Example 3 lies in that the cellarray is connected in such a manner that in two adjacent rows of cells,the conductive wires extend from a front surface of a cell at an end ofthe a^(th) row (a≧1) to form electrical connection with a back surfaceof a cell 31 at an adjacent end of the (a+1)^(th) row, so as to connectthe two adjacent rows of cells. The conductive wires for connecting thetwo adjacent rows of cells 31 are arranged in perpendicular to theconductive wires for connecting the adjacent cells 31 in the two rows.In such a way, a solar cell module A4 is obtained.

Testing Example 1

(1) Whether the metal wire in the solar cell module drifts is observedwith the naked eyes;

(2) According to the method disclosed in IEC904-1, the solar cellmodules manufactured in the above examples and the comparison exampleare tested with a single flash simulator under standard test conditions(STC): 1000 W/m² of light intensity, AM1.5 spectrum, and 25° C. Thephotoelectric conversion efficiency of each cell is recorded. Thetesting result is shown in Table 1.

TABLE 1 Solar cell module A1 D1 D2 A2 A3 A4 A5 Metal wire drifting noSlightly no no no no no phenomenon Photoelectric conversion 16.80%15.50% 15.30% 17.10% 17.05% 17.20% 17.30% efficiency Series resistance(mΩ) 451 498 515 442 445 427 425 Fill factor 0.779 0.764 0.742 0.7880.79 0.793 0.796 Open-circuit voltage (V) 37.84 37.44 37.52 37.85 37.7137.9 37.94 Short-circuit current (A) 9.166 8.712 8.836 9.22 9.206 9.1989.212 Working voltage (V) 31.54 30.49 30.32 31.86 31.84 31.97 31.92Working current (A) 8.568 8.176 8.117 8.633 8.611 8.651 8.717 Power (W)270.2 249.3 246.1 275 274.2 276.6 278.2

The fill factor refers to a ratio of the power at the maximum powerpoint of the solar cell module and the maximum power theoretically atzero resistance, and represents the proximity of the actual power withrespect to the theoretic maximum power, in which the greater the valueis, the higher the photoelectric conversion efficiency is. Generally,the series resistance is small, so the fill factor is great. Thephotoelectric conversion efficiency refers to a ratio of converting theoptical energy into electric energy by the module under a standardlighting condition (1000 W/m² of light intensity). The series resistanceis equivalent to the internal resistance of the solar module, in whichthe greater the value is, the poorer the performance of the module is.The fill factor represents a ratio of the actual maximum power and thetheoretical maximum power of the module, in which the greater the valueis, the better the performance of the module is. The open-circuitvoltage refers to the voltage of the module in an open circuit under astandard lighting condition. The short-circuit current refers to thecurrent of the module in a short circuit under a standard lightingcondition. The working voltage is the output voltage of the moduleworking with the largest power under a standard lighting condition. Theworking current is the output current of the module working with thelargest power under a standard lighting condition. The power is themaximum power which the module can reach under a standard lightingcondition.

It can be indicated from Table 1 that for the solar cell moduleaccording to the embodiments of the present disclosure, the metal wiredoes not drift, and higher photoelectric conversion efficiency can beobtained.

Testing Example 2

(1) Welding a metal wire onto a surface of a cell, the metal wire beingin perpendicular to secondary grid lines of the cell;

(2) Placing the cell horizontally at a testing position of a tensiletester, and pressing blocks on the cell, in which the pressing blocksare disposed at two sides of the metal wire, such that the cell will notbe pulled up during the test;

(3) Clamping the metal wire at a pull ring of a tension meter that formsan angle of 45° with the cell;

(4) Actuating the tension meter, such that the tension meter movesuniformly along a vertical direction, pulls up the metal wire from thesurface of the cell and records the pull data tested, in which the datais averaged to obtain the pull data of the metal wire. The testingresult is shown in Table 2.

TABLE 2 Module A1 D1 D2 A2 A3 A4 A5 Tensile force (N) 0.45 0.38 0.250.26 0.34 0.33 0.37

It can be indicated from Table 2 that for the solar cell moduleaccording to the embodiments of the present disclosure, greater tensileforce is needed to pull the metal wire away from the upper gall of thecell, which proves stronger stability of connection between the metalwire and the cell in the solar cell module.

In the specification, it is to be understood that terms such as“central,” “longitudinal,” “lateral,” “length,” “width,” “thickness,”“upper,” “lower,” “front,” “rear,” “left,” “right,” “vertical,”“horizontal,” “top,” “bottom,” “inner,” “outer,” “clockwise,” and“counterclockwise” should be construed to refer to the orientation asthen described or as shown in the drawings under discussion. Theserelative terms are for convenience of description and do not requirethat the present disclosure be constructed or operated in a particularorientation.

In addition, terms such as “first” and “second” are used herein forpurposes of description and are not intended to indicate or implyrelative importance or significance or to imply the number of indicatedtechnical features. Thus, the feature defined with “first” and “second”may comprise one or more of this feature. In the description of thepresent disclosure, “a plurality of” means two or more than two, unlessspecified otherwise.

In the present disclosure, unless specified or limited otherwise, astructure in which a first feature is “on” or “below” a second featuremay include an embodiment in which the first feature is in directcontact with the second feature, and may also include an embodiment inwhich the first feature and the second feature are not in direct contactwith each other, but are contacted via an additional feature formedtherebetween. Furthermore, a first feature “on,” “above,” or “on top of”a second feature may include an embodiment in which the first feature isright or obliquely “on,” “above,” or “on top of” the second feature, orjust means that the first feature is at a height higher than that of thesecond feature; while a first feature “below,” “under,” or “on bottomof” a second feature may include an embodiment in which the firstfeature is right or obliquely “below,” “under,” or “on bottom of” thesecond feature, or just means that the first feature is at a heightlower than that of the second feature.

Reference throughout this specification to “an embodiment,” “someembodiments,” or “some examples” means that a particular feature,structure, material, or characteristic described in connection with theembodiment or example is included in at least one embodiment or exampleof the present disclosure. Thus, these terms throughout thisspecification do not necessarily refer to the same embodiment or exampleof the present disclosure. Furthermore, the particular features,structures, materials, or characteristics may be combined in anysuitable manner in one or more embodiments or examples.

Although embodiments of the present disclosure have been shown anddescribed, it would be appreciated by those skilled in the art thatchanges, modifications, alternatives and variations can be made in theembodiments without departing from the scope of the present disclosure.

1. A solar cell array, comprising: a plurality of cells, each cellhaving a front surface on which light is incident when the cell is inoperation and a back surface opposite to the front surface; a pluralityof conductive wires, adjacent cells connected by the plurality ofconductive wires; secondary grid lines disposed on the front surface ofthe respective cell, the secondary grid lines comprising middlesecondary grid lines disposed in the middle of the respective cell andintersecting with the conductive wires, and edge secondary grid linesdisposed on the edges of the respective cell and non-intersecting withthe conductive wires; and short grid lines disposed on the front surfaceof the cell, the short grid lines connecting the edge secondary gridlines with the conductive wires or with at least one middle secondarygrid line.
 2. The solar cell array according to claim 1, wherein theadjacent cells are connected by the plurality of conductive wirescomprising a metal wire; the metal wire extends reciprocally between asurface of a first cell and a surface of a second cell adjacent to thefirst cell, so as to form at least two conductive wires.
 3. The solarcell array according to claim 2, wherein the metal wire breaks off at aturn formed by reciprocal extension after being connected with the firstand second cells.
 4. The solar cell array according to claim 2, whereinthe short grid lines are connected with the middle secondary grid linesclosest to the edge secondary grid lines.
 5. The solar cell arrayaccording to claim 2, wherein the short grid lines are connected withthe conductive wires.
 6. The solar cell array according to claim 5,wherein the short grid line and the metal wire at the front surface ofthe respective cell are connected at a turn formed by reciprocalextension.
 7. The solar cell array according to claim 1, wherein theshort grid line is perpendicular to the secondary grid line.
 8. Thesolar cell array according to claim 1, wherein the short grid line has awidth of 0.05 to 0.5 mm.
 9. The solar cell array according to claim 1,wherein the short grid line has a length of 1 to 10 mm.
 10. (canceled)11. The solar cell array according to claim 1, wherein there are 3 to 40short grid lines.
 12. The solar cell array according to claim 1, whereinthe conductive wires are welded with the secondary grid lines.
 13. Thesolar cell array according to claim 2, wherein the metal wire extendsreciprocally between a front surface of the first cell and a backsurface of the second cell. 14-21. (canceled)
 22. The solar cell arrayaccording to claim 2, wherein the metal wire is a copper wire. 23.(canceled)
 24. The solar cell array according to claim 2, wherein themetal wire extends reciprocally under strain, before being connectedwith the cells. 25-27. (canceled)
 28. A solar cell module, comprising anupper cover plate, a front adhesive layer, a solar cell array of claim1, a back adhesive layer and a back plate superposed in sequence. 29.The solar cell module according to claim 28, wherein adjacent cells areconnected by the plurality of conductive wires comprising a metal wire;the metal wire extends reciprocally between a surface of a first celland a surface of a second cell adjacent to the first cell, so as to format least two conductive wires; the front adhesive layer contacts withthe conductive wires directly and is disposed between the adjacentconductive wires. 30-35. (canceled)
 36. A method for manufacturing asolar cell module, comprising: forming a cell array with a plurality ofcells, the call array comprising a secondary grid line and a short gridline disposed on a front surface of the cell on which light is incidentwhen the cell is in operation, the secondary grid line including amiddle secondary grid line disposed in the middle of the respective celland intersected with a conductive wire, and an edge secondary grid linedisposed on the edge of the respective cell and non-intersected with theconductive wire, the short grid line connecting the edge secondary gridline with the conductive wire or with at least one middle secondary gridline; superposing an upper cover plate, a front adhesive layer, the cellarray, a back adhesive layer and a back plate in sequence, in which thefront surface of the cell faces the front adhesive layer, a back surfacethereof facing the back adhesive layer; and laminating the superposedlayers to obtain the solar cell module.
 37. The method according toclaim 36, further comprising: forming a plurality of the conductivewires by extending a metal wire reciprocally that extends between asurface of a first cell and a surface of a second cell adjacent to thefirst cell, such that adjacent cells are connected by the plurality ofconductive wires to form the cell array.
 38. The method according toclaim 37, wherein the metal wire extends reciprocally under a strain.39. The method according to claim 37, further comprising breaking themetal wire at a turn after the metal wire is connected with the cells.40-46. (canceled)